Manufacture of electrotype-plates.



C. P. COTTRELL.

MANUFACTURE OF ELECTROTYPE PLATES.

APPLICATION FILED JAN. 5, I911.

Patented May 11, 1915 2 SHEETS-SHEET lml'mmlm n HHIIIHHI II I C. P. COTTRELL.

MANUFACTURE OF ELECTROTYPE PLATES.

APPLICATION FILED JAN. 5, 1911.

1 139 9590 Patented May 11, 1915.

2 SHEETSSHEET 2.

- orrron.

CHARLES P. COTTRELL, or WESTERLY, nnonr. rsrnnn, ASSIGNOR, BY MESNE ASSIGN- MENTS, T 0. B. corranm. & sons COMPANY, or new YORK, N. Y., A conrom'rron or DELAWARE.

. MANUFACTURE or ELECTfiO'JJYPE-PLATES.

Specification of Letters Patent.

- To all whom it may concern Be it known that I, CHARLES P. Cormntt, a citizen of the United States, and resident of-Westerly, in the county of Washington and State of Rhode Island, have invented a new and useful Improvement in the Manufacture of Electrotype- Plates, of which the following is a specification.

The object of this invention is to provide a new method of producing an electrotype plate with gradations in its face.;,to insure proper printing values therein, which method will produce a better plate than heretofore and in a more economical and expeditious manner.

The present invention is directed to: the

method of producing -electrotype plates which consists in casting the backing up metal onto the back ofa shell while the face of the shell with an interposed overlay is held upon a suction surface whereby the backing up of the shell and the formation of the proper. gradations in the face of the plate are accomplished simultaneously.

In carrying out the invention, a reverse overlay is pasted onto the face of the shell in proper register therewith. The shell with its interposed reverse overlay is thenplaced upon a suction surface such, for instance, as the perforated top of a hollow backing paniforming part of an electrotype plate backing up machine. Means, such for instance as an exhaust pump, is used for exhausting theair from the backing pan and thus causing the shell with its interposed reverse overlay to be drawn snugly against Y said pan by suction exerted through-the per* forations in said top, which suction serves to draw the shell down into the depressions in the interposed reverse overlay. The backing pan is heated to the desired temperature and the molten backing up metal is then poured onto the back of the shell while the shell is held by suctionag'ainst the surface upon which it rests. If desired, the reverse overlay may be perforated so as to increase the suction effect upon that portion of the shell which is covered by the overlay so as to insure a more complete drawing down ofthe shell into the cutout places in the overlay. The pan and thereby'the backing up metal is allowed to cool while the shell with its interposed reverse overlay is held snugly against the surface upon which plane of the line A-A of Fig. 1, a portion of the perforated'top wall of the backing pan being broken away to illustrate more clearly the vacuum chamber, the heating means and the strengthening partitions which connect the top and bottom walls of the pan, Fig. 4 is a transverse vertical sec- PatentedMay1L1915.

tion taken in the plane of the line B -B' of Fig. 1, and Figs. 5, 6, 7, 8 and 9 show the several steps in the process. The baclnng up stand comprises side bars 1, 2, and end bars 3, 4, forming an open frame, which frame is supported by suitable legs 5. About midway the length of the stand, a yoke 6 uprises from the side bars 1 and 2 of. the frame, in which yoke is mounted a hand screw 7 carryinga pressure plate'or platen 8.

The hollow backing pan may be. slid along the stand into and out of position beneath the platen 8, .in the present instance by providing the side bars 1, 2, of the frame w1th tracks 9, 10, on which the opposite ends of the backing pan rest. Thisbacking pan comprises a perforated top 11 anda'" bottom v12 spaced therefrom to form ayacuum'chamber 13. Suitable strengthenmg partitions 14 are interposed between the top 11 and the bottom 12 of the backing pan for maintaining the top 11 in a per- 'fectly flat condition by preventing the same from warping or sagging out ofshape. I

A motor driven exhaust pump serves to exhaust the air from the interior of the hollow backing pan, which pump is shown hereln as a rotary exhaust pump 15 driven from an electric motor 16, both mounted upon a shelf 17 of the backing up stand, the pump 15 being connected to the interior of the backing pan through a flexible hose 18 i so as to permit the pan to be moved from one end of the frame to the other without disconnecting it from the exhaust pump. Any suitable means may be provided for heating the backing pan to the-desired tem- I perature that shown herein comprising an electric device including resistance coils 19 located within the hollow space or chamber 13. Electric current may be supplied to this heating device from any suitable source of electrical energy not shown herein.

In operation, the reverse overlay 20 is pasted onto the face of the electrotype shell 21 in proper register therewith and if desired the reverse overlay may be perforated for the purpose herein set forth. The shell with its interposed reverse overlay is pasted upon the perforated surface of the hollow backing pan. The pen may be heated 'to the desired temperature and the exhaust pump is started for exhausting the air from within the hollow backing pan and thus draw the electrotype shell with its interposed overlay snugly down onto the perforated surface of the backing pan, the shell at the same time being drawn down into the cutout portions of the overlay. The backing up metal is then poured onto the back of the electrotype shell. The pan and the backing up metal are allowed to cool while the shell with its interposed overlay is held snugly against the surface of the backing pan. If so desired pressure may be exerted upon the backing up metal by bringing the platen 8 into engagement therewith.

It will thus be seen that an electrotype plate is produced in which the proper gradations in its .face are formed at the same time that the shell is backed up. 7

It will thus be seen that the method hereinabove described produces a plate of superior quality in a very simple and expedit1ous manner.

while the face of the shell is 45 ing up metal onto between the face of the shell What I claim is 1. In the .manufacture of electrotype plates, simultaneously forming gradations in the face of the plate and casting the backing up metal onto the back of the shell held upon a suction surface with an overlay interposed between the face of the shell and said suction surface.

2. In the manufacture of electrotype plates, simultaneously forming gradations in the face of the plate and casting the backing up metal onto the back of the shell while the face of the shell'is held upon a heated suction surface with an overlay interposed between the face of the shell and said suction surface.

3. In the manufacture of electrotype plates, simultaneously forming gradations in the face of the plate and casting the backthe back of the shell. while the face of the shell is held upon a suction surface with a reverse overlay interposed and said suction surface.

'4. In the manufacture 'of electrotype plates, simultaneously forming gradations in the face of the plate and casting the backing up metal onto the back of the shell while the face of the shell is held upon a heated suction surface with a reverse overlay in of the shell and producing an electrotype plate with gradations in its printing face consisting in placing a shell face downward upon a heated surface with an interposed overlay in register therewith, holding the shell on said surface by suction and then casting the backing up metal onto the back 4 of the shell.

7. The-method of producing an electro type plate with gradations in its printing face consisting in placing a shell face downward upon a surface with an interposed reverse overlay in register therewith, holding the shell on said surface by suction and then casting the backing up metal onto the back of the shell.

8. The method of producing an electrotype plate with gradations in its printing face consisting in placing a shell face downward upon a heated surface with an interposed reverse overlay in register therewith, holding the shell on said surface by suction and then casting the backing up metal onto the back of the shell.

9. The method of producing an electrotype plate with gradations in its printing face consisting in placing a shell face downward upon a surface with an interposed overlay in register therewith, holding the shell on said surface by suction, casting the backing up metal onto the back of the shell and subjecting the backing up metal to pressure. I

10. The method of producing an electro type plate with gradations in its printing face consisting in placing a shell face down? ward upon a heated surface with an interposed overlay in register therewith, holding the shell on said surface by suction, casting the backing up metal onto the back of the shell and subjecting the backing up metal to pressure.

11. The method of producing an electrotype plate with gradations in its printing face consisting in placing a shell face downward upon a surface with an interposed reverse overlay'in register therewith, holding the shell on said surface by suction, casting the backing up metal onto the back of-the shell and subjecting the backing up metal to pressure.

12. The method of producing an electrotype plate with gradations in its printing face consisting in placing a'shell face downward upon a heated surface with an interposed reverse overlay in register therewith, holding the shell on said surface by suction, casting the backing up metal onto the back of the shell and subjecting the backing up metal to pressure.

13.. The method of producing an electrotype plate with gradations in its printing face consisting in pasting a reverse overlay in register onto the face 'of the electrotype shell, puncturing the overlay, placing the shell with its interposed overlay upon a surface, holding the shell on said surface by suction and casting the backing up metal onto the back of the shell. I

14:. The method of producing an electrotype plate with gradations in its printing face consisting in pasting a reverse overlay in register onto the face of the electrotype shell, puncturing the overlay, placing the shell with its interposed overlay upon a heated surface, holding the shell on said surface by suction, and casting the backing up metal onto the back of the shell.

In testimony, that I claim the foregoing as my invention, I have signed my name in presence of two Witnesses, this twenty seventh day of December A. D. 1910.

CHARLES P. COTTRELL.

Witnesses:

A. P. STILLMAN, A. G. WHITFORD. 

